The present invention relates to an apparatus for controlling the temperature of a rod at a laying head of a rod rolling line so as to be in conformity with a target value.
Rod rolling lines have a plurality of water cooling units disposed behind a continuous rolling mill for rapidly cooling the rods as they emerge from the rolling mill, and then gradually cooling the rods to meet the requirements for the desired quality of the rod. It is important from the standpoint of rod quality that the temperature at which the rod begins to be gradually cooled after being rapidly cooled be brought into conformity with a target value in the longitudinal direction of the rod.
It has been customary practice for the operator to control the temperature at which the rod is to begin gradual cooling by determining the rate of the flow of water through the water cooling units while referring to a rolling schedule, and correcting the rate of the flow of cooling water based on his or her individual judgment, formed on the basis of the difference between the reading on a thermometer located on the laying head where the rod is to begin cooling, and target temperatures. The prior process has sometimes failed to select the rate of flow of the cooling water properly according to the rolling schedule, and has completely failed to control skid marks or temperature changes in the rod material.